Emergency crews are working around the clock to clean an oil spill at West Rocks Middle School in Norwalk.

The fuel leaked out of a boiler and got into a nearby creek on Sunrise Hill Road.

State environmental officials say the cleanup could take up to a week. They estimate that between 200 and 300 gallons of fuel were spilled.

Department of Energy and Environmental Protection officials say the oil appears to have stayed on the surface and there's no evidence it has contaminated any soil. The agency is investigating what caused the boiler fitting to break in the first place.

For extended footage of the Norwalk oil spill, click on iO Extra on Channel 612.